This grower is fairly sure of this plant identification.
Pot is a real terracotta (not plastic) 21cm pot. Possibly T. pulegioides 'Foxley' - vigorous when not confined, unlike some Thymes!
Broad-leaved thyme, Thyme
Thymus pulegioides (Broad-leaved thyme). This species is a spreading subshrub. The leaves are aromatic oblong to lance-shaped and medium green. The flowers are borne in late spring and early summer with short whorled racemes of pink-purple blooms.
They are fully to marginally frost hardy. You should plant them out from early autumn through to early spring in a sunny site with moist, well-drained soil.
Useful for growing on banks and in rock gardens, troughs and paving.